This invention relates to a crushing apparatus for a pad material, and more particularly to the crushing apparatus for a pad material, which can crush closed cells in the pad material under vacuum suction after molding of the pad material having the closed cells.
Hitherto a pad material of a vehicular seat or the like has been formed by foam-molding a synthetic resin such as polyurethane resin or the like. In case that this pad material has closed cells, an operation of crushing the closed cells in the pad material has been made in order to prevent a performance (such as resiliency or the like) of the pad material from lowering owing to contraction of volume of closed cells with temperature lowering. A variety of crushing apparatuses for crushing the closed cells in the pad material has been proposed and put into practical use. For example, with a crushing apparatus as shown in FIG. 7A, the pad material 1' of the vehicular seat or the like is inserted into between crushing rolls 3, 3 disposed up and down, thereby crushing the closed cells in the pad material 1'.
With another crushing apparatus as shown in FIG. 7B, the closed cells in the pad material 1' are crushed as follows: First, the pad material 1' is placed in a vacuum box 5 upon connecting a vacuum mechanism to a suction opening 6 formed at one side of the vacuum box 5. Then, vacuum suction is made through this suction opening 6 thereby expanding the closed cells in the pad material 1'. Additionally, with a further crushing apparatus as shown in FIG. 7C, the closed cells in the pad material 1' are crushed as follows: First, the pad material 1' is placed on a vacuum box jig 8 disposed at a lower side of a vacuum box. Then, the upper part of the pad material 1' is covered with a fabric 9 having no air permeability, disposed over the vacuum box jig 8 upon connecting a vacuum mechanism to a suction opening 10 formed at one side of the vacuum box jig 8. Thereafter, vacuum suction is made through this suction opening 10.
In connection with the above crushing apparatus shown in FIG. 7A, there has been a case where the above-mentioned pad material 1' is foam-molded integral with a seat frame formed of a wire frame or the like. In this case, when the pad material 1' is inserted into between the crushing rolls 3, 3 disposed up and down, there arises the fear of the seat frame formed of the wire frame or the like to be formed integral with the foam-molded pad material 1' being bent or deformed.
Additionally, in connection with the crushing apparatus as shown in FIG. 7B, in a case where vacuum suction is made through the suction opening 6 at one side of the vacuum box 5 upon storing the pad material 1' in the vacuum box 5, it is difficult to crush the closed cells in the pad material 1' so that a sufficient crushing effect cannot be obtained on the closed cells in the pad material 1'.
Further, in connection with the crushing apparatus as shown in FIG. 7C, in a case where the fabric 9 having no air permeability and disposed above the vacuum box jig 8 is covered on the upper part of the pad material 1' upon placing the pad material 1' on the vacuum box jig 8, it is required to provide such a shape as to correspond to the external shape of the pad material 1' to the surface of the vacuum box jig 8. This complicates production of the vacuum box jig 8, thereby providing a defect of making a cost-up. Additionally, there is the fear of rubbing being made between the fabric 9 and the pad material 1' thereby generating static electricity.